i don’t know about you, loyal readers, but the weather here in georgia has me reaching for the tissue box regularly these days.  i wouldn’t categorize myself as severely allergic to the spring weather; however, something in the air keeps me sneezing day in and day out.  i suppose it doesn’t help that i have the windows open when i am home, but i just can’t keep the lovely breeze away when it’s so nice!

anyway, when you feel a sneeze coming on but not quite there, you’ve probably been told by someone (perhaps a mother, grandparent, or other wise individual) to look at a light or the sun to get that sneeze out of your system.  well, i know this little trick works nearly every time for me and recently it got me wondering about why it actually works.  good thing there’s a thing called the internet to answer this puzzling question!

after reading a couple of articles (article 1 and article 2), it turns out that there isn’t much concrete explanation (although there is plenty of speculation) as to why looking at light activates the sneeze action in some people.  although originally thought to be caused by heat, the general theory now is that this “photic sneeze reflex” is caused by irritation in the nose, which can be triggered when the trigeminal nerve fires.  this trigeminal nerve is close in proximity to the optic nerve, so when the eyes’ pupils constrict in response to a sudden flood of light to the retina, the nose also reacts.

now, part of what you read were the words “in some people.”  that’s right.  this phenomenon actually has genetic roots.  not from the x or y chromosome, but from an autosomal-dominant gene you inherit from at least one of your parents.  with that, it’s estimated that only about 10% to 35% of the world’s population is affected by the photic sneeze reflex.  well, doesn’t that just make me feel special!

p.s.  the best part about the photic sneeze reflex?  the incredibly clever acronym created many moons ago:  autosomal-dominant compelling helio-opthalmic outburst syndrome.  aka, ACHOO!  the more you know.  😀